Ivanka Trump was booed and hissed on stage Tuesday in Germany, according to reporters who were at the W20—a Group of 20 conference focused on international women’s issues. Ivanka Trump called her father, the 45th president of the United States, a “tremendous champion” of families, reportedly leading to the hostile audience reaction. President Trump tweeted around the same time noting that he is “proud” of his daughter for speaking at the conference and “for her leadership on these important issues.”